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 * The Universal Permissive License (UPL), Version 1.0
 *
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 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
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 * use, sell, offer for sale, import, export, have made, and have sold the
 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
 *
 * This license is subject to the following condition:
 *
 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must be included in all copies or substantial
 * portions of the Software.
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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package com.oracle.truffle.dsl.processor.parser;

import java.lang.annotation.Annotation;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.Element;
import javax.lang.model.element.ElementKind;
import javax.lang.model.element.ExecutableElement;
import javax.tools.Diagnostic.Kind;

import com.oracle.truffle.dsl.processor.CompileErrorException;
import com.oracle.truffle.dsl.processor.Log;
import com.oracle.truffle.dsl.processor.ProcessorContext;
import com.oracle.truffle.dsl.processor.java.ElementUtils;
import com.oracle.truffle.dsl.processor.model.MessageContainer;
import com.oracle.truffle.dsl.processor.model.MessageContainer.Message;
import com.oracle.truffle.dsl.processor.model.NodeData;

/**
 * THIS IS NOT PUBLIC API.
 */
public abstract class AbstractParser<M extends MessageContainer> {

    protected final ProcessorContext context;
    protected final ProcessingEnvironment processingEnv;

    protected final Log log;

    public AbstractParser() {
        this.context = ProcessorContext.getInstance();
        this.processingEnv = context.getEnvironment();
        this.log = context.getLog();
    }

    public final M parse(Element element) {
        M model = null;
        try {
            AnnotationMirror mirror = null;
            if (getAnnotationType() != null) {
                mirror = ElementUtils.findAnnotationMirror(processingEnv, element.getAnnotationMirrors(), getAnnotationType());
            }

            if (!context.getTruffleTypes().verify(context, element, mirror)) {
                return null;
            }
            model = parse(element, mirror);
            if (model == null) {
                return null;
            }

            redirectMessages(new HashSet<MessageContainer>(), model, model);
            model.emitMessages(context, log);
            if (model instanceof NodeData) {
                return model;
            } else {
                return filterErrorElements(model);
            }
        } catch (CompileErrorException e) {
            log.message(Kind.WARNING, element, null, null, "The truffle processor could not parse class due to error: %s", e.getMessage());
            return null;
        }
    }

    private void redirectMessages(Set<MessageContainer> visitedSinks, MessageContainer model, MessageContainer baseContainer) {
        List<Message> messages = model.getMessages();
        for (int i = messages.size() - 1; i >= 0; i--) {
            Message message = messages.get(i);
            if (!ElementUtils.isEnclosedIn(baseContainer.getMessageElement(), message.getOriginalContainer().getMessageElement())) {
                // redirect message
                MessageContainer original = message.getOriginalContainer();
                String text = wrapText(original.getMessageElement(), original.getMessageAnnotation(), message.getText());
                Message redirectedMessage = new Message(null, null, baseContainer, text, message.getKind());
                model.getMessages().remove(i);
                baseContainer.getMessages().add(redirectedMessage);
            }
        }

        for (MessageContainer childContainer : model) {
            if (visitedSinks.contains(childContainer)) {
                continue;
            }
            visitedSinks.add(childContainer);

            MessageContainer newBase = baseContainer;
            if (childContainer.getBaseContainer() != null) {
                newBase = childContainer.getBaseContainer();
            }
            redirectMessages(visitedSinks, childContainer, newBase);
        }
    }

    private static String wrapText(Element element, AnnotationMirror mirror, String text) {
        StringBuilder b = new StringBuilder();
        if (element != null) {
            if (element.getKind() == ElementKind.METHOD) {
                b.append("Method " + ElementUtils.createReferenceName((ExecutableElement) element));
            } else {
                b.append("Element " + element.getSimpleName());
            }
        }
        if (mirror != null) {
            b.append(" at annotation @" + ElementUtils.getSimpleName(mirror.getAnnotationType()).trim());
        }

        if (b.length() > 0) {
            b.append(" is erroneous: ").append(text);
            return b.toString();
        } else {
            return text;
        }
    }

    protected M filterErrorElements(M model) {
        return model.hasErrors() ? null : model;
    }

    protected abstract M parse(Element element, AnnotationMirror mirror);

    public abstract Class<? extends Annotation> getAnnotationType();

    public boolean isDelegateToRootDeclaredType() {
        return false;
    }

    public List<Class<? extends Annotation>> getAllAnnotationTypes() {
        List<Class<? extends Annotation>> list = new ArrayList<>();
        if (getAnnotationType() != null) {
            list.add(getAnnotationType());
        }
        list.addAll(getTypeDelegatedAnnotationTypes());
        return list;
    }

    public List<Class<? extends Annotation>> getTypeDelegatedAnnotationTypes() {
        return Collections.emptyList();
    }

}
